Engineer&#39;s level



Sept. 2L w43., A. N. BRUNsoN ENGINEER S LEVEL Filed Feb. 2s, 1942 Patented Sept. 21, 1943 This invention. relatesto improvements in an engineers' level; I o

The general object .of the invention is to provide a surveying instrument' such vasa level with never supporting means for atele'scope whereby greater accuracy is secured.' Q A more' specific' object of ,the inventioils. Vto provide a never spindle 'mountingfor the tere'- scope. of `a surveying instrument. I I

anotherobieot of, the invention .is to provide i aiingineers `level; includinga novell post lconi' struction. Y

Ari additio-riaiobieoi orme invention, is to' provide an improved. engineers level wherein a A'no vei telescope is provided. 'r

Another object of the invention isl to"provid`e an improved mounting for the telescope o-f a surveyors instrument which is constructed so that the parts remain accurate regardless of expansion and contraction.

Other objects and advantages of this invention lwill be apparent from the following description taken in connection with the accompanying drawing, wherein:

Fig. 1 is a central sectional view showing an y.engineers level embodying the features of my invention;

Fig. 2 is an enlarged fragmentary section showing the lower partof the mounting, and

Fig. 3 is a View similar to Fig. 2 showing the upper part of the mounting. i

This invention is an improvement on the invention shown in my prior Patents No. 2,208,014, granted July 16, 1940, and No. 2,164,051, granted June 27, 1939, and No. 2,280,057, granted April 21, 1942. While my prior patents disclose n ovel means for supporting the spindle and shell of a surveying instrument in anti-friction bearings, the present application discloses further improved details of construction which have been found highly advantageous in actual practice, particularly in constructions wherein the available space for mounting bearings is limited.

, spindle 3S.

aperture I9* m which a post 20 is mountedg, The post includes a 'lower threaded portion :Ui-with a n 'afnge v 22;y disposed, intermediate ,the length of the post. Y'The' ange' 211!r is outwardly directed and engagesthe lowerwalr 23 ora recess V2'4 in the' l'eveilrg head l2.l H'Ihe post includesja cylini drical` portionfZ abovetheange 22 vand above `the portion 2,5" includes' an ienlargediendlportion 2,6 from which a collar Z'I'extehds'. AtJ thekiunc- Vtion of ,the` portions 26 arid jlarrange a Vplane engages the outeru element Y34Ij of an anti'fiiiction ball race-3.? which inl'des anirrierielementj- The inner" element?? is` Yerieienl In ,a dans?. .34 on a retaining' "ring V35'. 4The lowerV vend fof-"the post is closed by `a threaded closure, 35. I

Mounted within the sleeve I .provide a This spindle 36 is cylindrical and includes a lower reduced cylindrical lportion 3'I which receives the inner ball race3'3 and also receives the retaining ring 35. includes a threaded aperture at its lower end. In

thisiaperture I arrange a.v cap 38 .the head 39 of y, ,4 which engages the lower end of the ring tol hold the parts assembled.

Theupper portion of the spindle is provided ywith an outwardly projecting flange 40 (see Fig.

s), the lower face of which is beveled as at 4| i with the bevelled portion engaging the ball memyIn the accompanying drawing my invention is i shown as embodied in an engineers level lwhich is indicated generally at I0. As shown the level includes a foot plate I I on which a leveling head I2 is supported by a plurality of screws I3. Each bers 29 previously described. Above the beve'lled portion 4I the flange 40 has a cylindricalouter face 42. Spaced from the collar 21 on the post and in'this space I arrange a dirt and dust excluding seal 43.k

4 Above the flange 40 the spindle is of reduced -'diameter and is threaded as ai; 42'. Mounted on the threaded portion 42' I arrange a threaded coupling 45. This coupling 45 includes alower cylindrical recess 46 in which the cylindrical upl shoulders/46 and II'I I arrange a clamp ring 48.

of the screws I3 includes a head I4 terminating Y The screws i The clamp -ringincludes'a clamp screw assembly 49 and a slow motion assembly 50. The clamp ring, the clamp screw 49 and theslow motion assembly 50 form no part of the presentinvention.

'I'he upper portion of the coupling 45 is of reduced diameter and is threaded as at 5I and on this threaded portion .5I I mountv a level bar j cuneo rari-eur The portion 3IV 52. Mounted upon the level bar 52 I show a level vial 53 which is supported in the level bar 52 which is hollow and is provided with end closures 54. At one end the level vial is pivoted as at 55 and at the other end includes a projection 56 engaged by an adjusting screw 5l which includes a lock nut 58. A leaf spring 59 on the portion 56 normally urges the vial against the upper end of the 4adjusting nutu'l. The vial is viewed through a viewing aperture 60.

Mounted upon the level bars 52 I show a telescope 6I. The telescope includes an objective lens 62, a negative lens tube 63, a cross wire reticule 64 and an eye piece assembly 65. The

negative lens tube 63 is slidable in a tube 66 and is shifted by turning the thumb screw G1 on which a gear E8 is mounted. The gear 58 meshes with a rack 69 on the tube 63.

Between the tubes 63 and B6 I arrange a ball bearing retainer l which is provided with an elongated slot 1| which permits passage of a shaft l2 on which the thumb screw 61 is mounted. Ballsflil' are arranged in suitable holes in the retainer l. The balls l2' engage the tubes 63 and liliV and thus form asupport for the tube 63.

The eye piece assembly 65 includes an eye piece 'l2 and the assembly includes a threaded cap member 'i3 which threads into` the end of the telescope. The assembly supports a tube 14 and a second` tube 'i5 surrounding the tube 14. The tube 15 engages anti-friction balls 16 which are held in a tubular retainer 'H and which engage the inner surface of a sleeve 18, A pin 'i9 in the tube 'l5 and ,movable in a slot 80 limits movement `of the eye piece.

From the foregoing ,descriptionit will be apparent that I have invented a novel engineers Cil level which can be economically manufactured and is highly eiiicient for the intended purpose. Having thus described my invention, I claim: A support for a surveying instrument telescope comprising a foot plate, a hollow post universally the latter, a sleeve within and directly engaging said hollow post, a bearing within said post and engaging said sleeve, a spindle within and directly engaging the sleeve, said spindle having a reduced lower end slidably engaging said bearing, means to hold said bearing in place, said post having an enlarged upper end and having an integral annular collar at the extreme upper end thereof, said collar forming an upper in terior bearing recess, balls in said recess, said spindle having an outwardly directed flange adjacent the upper end thereof, said spindle flange having an inclined `bearing face engaging said balls, sealing means lbetween said collar and spindle flange for excluding dirt from said balls, and a coupling member mounted directly on said .pin dle, said coupling member having a downwardly directed skirt forming a cylindrical recess, said integral collar on said post being arranged in said last mentioned recess, the upper end of said sleeve terminating below the bearing recess in said collar.

AMBER, N. BRUNSON. 

